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backtracks

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backtracks is a python package to fit relative astrometry with background helical motion tracks, to discern directly imaged planets :ringed_planet: from contaminant sources :dizzy: :star:

The code is written and developed by Gilles Otten (@gotten), William Balmer (@wbalmer), and Tomas Stolker (@tomasstolker).

Documentation

Documentation can be found at http://backtracks.readthedocs.io <https://backtracks.readthedocs.io/en/latest/>_.

Tutorial

A Jupyter notebook <https://backtracks.readthedocs.io/en/latest/tutorial.html> will show you how to use backtracks by reproducing the result in Nielsen et al. (2017) <https://ui.adsabs.harvard.edu/abs/2017AJ....154..218N/abstract> and Wagner et al. (2022) <https://ui.adsabs.harvard.edu/abs/2022AJ....163...80W/abstract>_ for the case of the former exoplanet candidate around HD 131339 A.

Attribution

If you use backtracks in your published work, please cite our Astrophysics Source Code Library entry, https://ascl.net/code/v/3755, and/or provide a footnote/acknowledgement linking to our package. Thank you!

Details

eDR3 Distance prior summary file from Bailer-Jones et al. (2021) <https://ui.adsabs.harvard.edu/abs/2021AJ....161..147B/abstract>_.
Example of HD 131399Ab uses data from Wagner et al. (2022) <https://ui.adsabs.harvard.edu/abs/2022AJ....163...80W/abstract> and Nielsen et al. (2017) <https://ui.adsabs.harvard.edu/abs/2017AJ....154..218N/abstract>. Thank you to Kevin Wagner for providing the latest astrometry!
Log-likelihood and some utility functions borrowed heavily from orbitize! <https://github.com/sblunt/orbitize/>_ (BSD 3-clause).
PPF of multivariate normal borrowed from pints <https://github.com/pints-team/pints>_ (BSD 3-clause).

Installation

Currently requires and python 3.9-3.11 ish and astropy, corner, dynesty, matplotlib, numpy, novas, novas_de405, and their dependencies. Note that novas is not supported on Windows. You can create a working environment using conda+pip via a few lines of code:

.. code-block:: console

$ conda create python=3.11 -n backtracks
$ conda activate backtracks
$ conda install pip
$ pip install backtracks

Or, to clone the repo and install in development mode (we recommend this, as the code is a work in progress and you can easily fix bugs you will likely encounter this way):

.. code-block:: console

$ conda create python=3.11 -n backtracks
$ conda activate backtracks
$ conda install pip
$ git clone https://github.com/wbalmer/backtracks.git
$ cd backtracks
$ pip install -e .

Then, test your installation:

.. code-block:: python

>>> from backtracks import System

wbalmer / backtracks